Thanks, Rev. Greco. I am very interested in the exegetical case that the other two words used in those passages refer to songs outside the book of psalms. As of now I wouldn't be able to defend this if someone asked me.
The Apostles seem to have known it well, and they were fishermen, a tax collector, etc., weren't they? Plus if they sang the psalms in synagogue and if they were referred to as "hymns" (I don't know), that would also inform their understanding of the word.anyone other than a learned Jew well steeped in the LXX (probably less than 0.00000001% of the population)